Yes, you can generally leave the airport during a layover, but the feasibility depends on your nationality, the country you are in, and the time available. For domestic flights, you can walk out freely, though you must clear security again to return. For international layovers, you must pass through Immigration and Customs, which requires a valid visa or entry permit (like an ESTA or ETIAS). In 2026, most experts recommend at least 6 hours for a domestic exit and 8 to 10 hours for an international one. This accounts for the time to deplane, travel to the city center, and the requirement to be back at least 2–3 hours before your next departure. If your connection is short, it is safer to stay in the terminal to avoid missing your flight due to unexpected traffic or long security lines.